1. Field of the Invention
The present invention relates to extracting and cleaning cotton. More specifically, the present invention provides an apparatus and method for reducing cotton fiber waste by lint cleaners.
2. Description of the Prior Art
Over 80 million bales of cotton are produced annually in the world. These cottons are harvested by hand or mechanically by machines called spindle-harvesters or cotton strippers. Depending upon the harvesting method, these cottons are precleaned through various machines in a cotton-gin processing plant and dried prior to the fiber being separated from the seed. After the fiber is separated from the seed, it is further cleaned by different types of machines that are typically called lint cleaners. Lint cleaners were developed specifically for removing leaf particles, motes, grass, and bark that remain in cotton after seed cotton cleaning, extracting, and ginning. They were developed and improved in conjunction with the transition from manual to mechanized harvesting of cotton in the United States during the 1950's. Virtually all gins in the United States have lint-cleaning facilities, and over four-fifths of the gins have two or more stages of lint cleaning.
The most common lint cleaner in the ginning industry is called a saw-type lint cleaner which removes 15 to 30 pounds of material per bale, with much of this material being usable fiber. In terms of principles of operation, a thin batt of cotton fiber is fed mechanically onto a cylinder wound with fine-tooth saws. The saws grasp the cotton fiber and pull it between the saw cylinder and a set of closely spaced (0.06 to 0.12 inches) cleaning points commonly called grid bars. Saw-type lint cleaners typically have 5 to 8 grid bars each. Each grid bar location creates a cleaning point that separates and ejects cotton fiber and foreign matter from the saw toothed-engaged cotton. The first grid bar separates and ejects a high percentage of foreign matter and a low percentage of cotton fiber. The percentage of foreign matter separated and ejected decreases dramatically and the percentage of cotton fiber separated and ejected increases dramatically as the number of grid bars increase. For example in a 5-grid bar machine, about 25, 23, 22, 15, and 15% by weight of the foreign material is separated and ejected by the first, second, third, fourth and fifth grid bars, respectively. Therefore, as the saw toothed-engaged cotton fiber progresses successively against and under grid bars, decreasing amounts of foreign matter and increasing amounts of cotton fiber are removed concomitant with an increase in damage to the saw toothed-engaged cotton. Furthermore, cotton fiber is separated from the saw toothed-engaged cotton and ejected, even if no foreign matter is present. Thus, substantial money is lost.
About 20% of all cotton processed today in the United States requires only a portion of cleaning available from conventional saw-type lint cleaners. Thus, some cotton is over-processed and a substantial amount of cotton fiber is lost. A primary reason for such a substantial amount of cotton lost is that conventional saw-type lint cleaners typically have too many grid bars, for example 5 to 8 grid bars.
Some cottons obviously contain far more foreign matter than others. Therefore, certain cottons would require the use of all available grid bars in addition to perhaps another lint cleaner. Depending upon the foreign matter or color, as little as one grid bar or as many as five or more grid bars per machine and as many as three machines may be required to meet market demands. There is currently no technology available which would permit use of less than all of the grid bars available for any particular lint cleaning machine. If an apparatus and method were available that would allow the selection of less than the total number of grid bars available, the amount of cotton fiber lost would be reduced. Thus, only the required number of grid bars needed for any particular cotton would be employed, and the cost and waste of cotton fiber would be substantially reduced, especially for relatively clean cotton which requires only one or two grid bars. If a cotton processor possessed the ability to use or not use each individual grid bar, fiber wastage could be decreased by 5 to 15 pounds per bale.
Therefore, what is needed and what has been invented is an apparatus and a method for reducing the loss and waste of cotton fiber as cotton is being processed through a lint cleaner. What is further needed and what has been invented is an apparatus and a method that allow prescription processing of cotton through a lint cleaner based upon its requirements, rather than processing the cotton through the entire lint cleaner regardless of its needs.